• Journal of the Korean Physical Society
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• 제73권11호
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• pp.1794-1798
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• 2018

We have grown famatinite $Cu_3SbS_4$ films by using sulfurization of Cu/Sb stack film. Sulfurization at $500^{\circ}C$ produced famatinite $Cu_3SbS_4$ phase, while $400^{\circ}C$ and $450^{\circ}C$ sulfurization exhibited unreacted and mixed phases. The fabricated $Cu_3SbS_4$ film showed S-deficiency, and secondary phase of $Cu_{12}Sb_4S_{13}$. The secondary phase was confirmed by X-ray diffraction, Raman spectroscopy, photoluminescence and external quantum efficiency measurements. We have also fabricated solar cell in substrate type structure, ITO/ZnO/(Zn,Sn)O/$Cu_3SbS_4$/Mo/glass, where $Cu_3SbS_4$ was used as a absorber layer and (Zn,Sn)O was employed as a Cd-free buffer. Our best cell showed power conversion efficiency of 0.198%. Characterization results of $Cu_3SbS_4$ absorber indicates deep defect (due to S-deficiency) and low shunt resistance (due to $Cu_{12}Sb_4S_{13}$ phase). Thus in order to improve the cell efficiency, it is required to grow high quality $Cu_3SbS_4$ film with no S-deficiency and no secondary phase.

• 한국전기전자재료학회논문지
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• 제32권6호
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• pp.496-500
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• 2019

In this study, we investigate the effect of an Sb-deficiency on the thermoelectric properties of double-filled n-type skutterudite ($In_{0.05}Yb_{0.15}Co_4Sb_{12-x}$). Samples were prepared by encapsulated induction melting, consecutive long-time annealing, and finally spark plasma sintering processes. The Sb-deficient sample contained a $CoSb_2$ secondary phase. Both the double-filled n-type skutterudite pristine and Sb-deficient samples showed metallic behavior in electrical conductivity with increasing temperature. The carrier concentration of the Sb-deficient sample decreased compared with that of the pristine sample. Due to a decrease in carrier concentration, the Sb deficient sample showed decreased electrical conductivity and an increased Seebeck coefficient compared with the conductivity and coefficient of the pristine sample. Furthermore, the Sb deficient sample showed an increase in the power factor (${\sigma}{\cdot}S^2$); the power factor maximum shifted to athe lower temperature side than ones of the pristine sample. As a result, the Sb-deficient sample represents an improved average figure of merit (ZT) and a $ZT_{max}$ temperature lower than that of the pristine sample. Therefore, we propose that Sb-deficient double-filled n-type skutterudite thermoelectric material ($In_{0.05}Yb_{0.15}Co_4Sb_{12-x}$) be used in the 573~673 K temperature range.

• 동의신경정신과학회지
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• 제34권3호
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• pp.141-150
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• 2023

Objectives: This study aimed to comprehend the characteristics of Korean medicine patterns in relation to varying degrees of cognitive impairment in an elderly population. Methods: The dataset included 127 elderly individuals with cognitive impairment obtained from three Korean medicine hospitals between 2018 and 2021. The participants were categorized into two groups based on Clinical Dementia Rating-Sum of Boxes (CDR-SB) scores: those with questionable impairment (QI) and those with very mild dementia (VMD). A diagnostic framework for Korean medicine patterns encompassing Qi deficiency, Yin deficiency, Phlegm dampness, and Heat-fire was employed. Liver blood markers, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), and the AST/ALT ratio, were also analyzed. Results: The scores of the cognitive assessment tools (MoCA-K, MMSE-DS, and K-IADL) of the QI group significantly differed from those of the VMD group. CDR-SB exhibited a positive correlation with the scores of each pattern of Qi deficiency, Yin deficiency, Phlegm dampness, and Heat-fire, whereas ALT and AST values displayed negative correlations. Binomial logistic analysis, controlling for potential confounders, such as age, education years, body mass index, the presence of chronic disease, and the presence of medication, verified that the VMD group showed higher pattern scores and lower ALT and AST values than the QI group. Conclusions: Increases in pattern scores along with decreased AST and ALT levels might be indicative of more severe cognitive impairment.

• 대한화장품학회지
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• 제35권1호
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• pp.27-32
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• 2009

인간의 모발은 금속을 배설하는 시스템이며 몸에서 금속의 함유량을 반영한다. 본 연구에서는 현대인의 유해 중금속 노출 정도를 파악하고, 질병 예방 혹은 환경 개선 예측의 도구로서 모발 분석의 필요성에 대해 알아보고자 하였다. 많은 만성 질환은 금속의 축척과 관련이 있을 것으로 예상되며 몇몇은 유해 중금속과 관련이 있다. 이에 서울, 수도권지역에 거주하는 20대에서 40대의 성인 남녀 120명(남자 61명, 여자 59명)을 대상으로 시료를 채취한 후 유도 결합 플라즈마 질량 분석기를 사용하여 Hg, Pb, Cd, Al, As, U, Bi, Sb, Ba, Be의 10가지의 독성 미네랄의 함량을 측정하였다. 분석 결과 20대의 유해 중금속 함량 분석에서는 기준치 이상을 보이는 원소가 없었으나, 알루미늄(Al)과 안티몬(Sb)의 수치가 높게 나타났다. 30대의 경우도 기준치 이상의 원소는 보이지 않았으나 수은(Hg)과 알루미늄(Al)의 농도가 높게 나타났다. 40대의 경우 기준치 이상의 수은(Hg)과 안티몬(Sb)이 검출되었다. 또한 성별에서는 남성의 경우 수은(Hg)이, 여성의 경우 안티몬(Sb)이 기준치보다 높은 것으로 나타났다. 산업의 발달로 인해 유해 중금속은 여러 가지 경로를 통해 우리 몸속으로 들어오며, 몸 밖으로 배출되지 못하고 인체에 계속 쌓여 면역 기능과 호르몬 기능이 저하시키고 질병을 유발하게 된다. 이에 유해 중금속의 노출 정도를 분석하여 그에 맞는 대체요법을 시행한다면 질병을 예방하고 환경을 예측할 수 있다. 인체 내에 중금속의 추적 상태를 알아보기 위해 우리나라에서도 모발 분석에 대한 관심과 연구를 통해 우리의 건강 상태를 유지하기 위한 수단으로 활용되기를 시사하는 바이다.

• Nuclear Engineering and Technology
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• 제41권5호
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• pp.655-676
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• 2009

The first-ever integral effect test for simulating a guillotine break of a DVI (Direct Vessel Injection) line of the APR1400 was carried out with the ATLAS (Advanced Thermal-hydraulic Test Loop for Accident Simulation) from the same prototypic pressure and temperature conditions as those of the APR1400. The major thermal hydraulic behaviors during a DVI line break accident were identified and investigated experimentally. A method for estimating the break flow based on a balance between the change in RCS inventory and the injection flow is proposed to overcome a direct break low measurement deficiency. A post-test calculation was performed with a best-estimate safety analysis code MARS 3.1 to examine its prediction capability and to identify any code deficiencies for the thermal hydraulic phenomena occurring during the DVI line break accidents. On the whole, the prediction of the MARS code shows a good agreement with the measured data. However, the code predicted a higher core level than did the data just before a loop seal clearing occurs, leading to no increase in the peak cladding temperature. The code also produced a more rapid decrease in the downcomer water level than was predicted by the data. These observable disagreements are thought to be caused by uncertainties in predicting countercurrent flow or condensation phenomena in a downcomer region. The present integral effect test data will be used to support the present conservative safety analysis methodology and to develop a new best-estimate safety analysis methodology for DVI line break accidents of the APR1400.

• 한국광물학회지
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• 제16권1호
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• pp.1-17
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• 2003

유비철석 + 황철석 + 육방정계 자류철석으로 구성되는“삼종동시접촉”을 수반하는 유비철석의 화학조성은 광화작용의 II단계에서 유용한 지온계를 제공한다. 연구에 따르면 이 지온계는 황분압 f($S_2$)=$10^{-9.5}$ 기압하에서, 지온 T = $330^{\circ}C$에서 형성된 것으로 밝혀졌다. 황철석 -육방정계 자류철석 완충곡선에서는 이 두 변수가 T= $315∼345^{\circ}C$와 f( $S_2$)=$10^{-1}$0.5/∼$10^{-9}$ 기압에 해당됨을 보여 준다. 이지역에서 산출되는 안티모니를 포함하는 자류철석(Ic)는 무게 퍼센트가 4.95∼8.91에 달하는 상대적인 높은 간을 보이며, 철은 과다한 반면 양이온은 결핍되는 현상을 보인다. 자류철석에서 이러한 높은 안티모니 함량은 단일 입자내에서는 처음 알려진 것이다. 이러한 높은 안티모니 함량이 자류철석 Ic를 지온계로서 작용할 수 없게 만들었다. 광화작용 III단계에서의 4쌍의 자류철석과 섬아연석의 전자현미분석 결과는 T : $310∼340^{\circ}C$와 f(S2)=$10^{ }$$∼10^{-9}$ / atm을 보이며, 이 값은 Fe-As-S 계에서 추정된 값과 일치한다...